1. Field of the Invention
The present invention relates to a bandsaw or jigsaw accessory. More specifically, it relates to a device attachable to the worktable of the saw where a slidable pivot pin that engages either the workpiece itself or a frictionally padded template allows for the cutting of a circle or a partial arcuate edge by allowing the user to select a radius and then rotate the workpiece or template on the pivot pin relative to the cutting plane of the saw.
2. Description of the Prior Art
When working with wood, especially with a band or jigsaw, one of the more difficult tasks is to cut smooth arcs or circles in the workpiece. In many cases, often the woodworker will simply trace out the circle or arc with a protractor or similar geometric instrument and then cut the desired shape by carefully manipulating the piece so that the blade follows the trace, thus producing the shape intended. This is made difficult by the moving blade itself exerting force against the workpiece making the process slow and potentially dangerous. In other cases, human error can ruin the piece, thus wasting the raw materials and adding time to the project. There have been a number of proposed solutions to this problem but as will be seen, they are complicated and require cumbersome or permanent attachments to the saw table, thus forcing the user to assemble and disassemble the device every time one needs to use it.
U.S. Pat. No. 149,654 issued on Apr. 17, 1874 to Edward H. Hanna et al. discloses an improvement for saw tables wherein a pitch board has two screws that attach it to the bed plate of the saw table. The angle of the pitch board relative to the horizontal bed plate is fixed by two adjusting bars that are attached to the pitch board and the bed, and that engage one another. There is a graduated radius plate attached to the pitch board and to a pivot bolt. The workpiece is clamped to the pitch board and the graduated radius plate is adjusted to the desired mark. The entire assembly can then be rotated about the pivot bolt thus cutting the desired arc.
U.S. Pat. No. 207,455 issued on Aug. 27, 1878 to Charles Stout discloses a barrel head machine wherein a pin is mounted on the saw table. This mounting can be adjustable with a screw running perpendicular to the cutting plane of the saw. Mounted on the pin is a table. On the table are a number of peg holes and another screw which acts as a sliding nut carrying a fence. Both the fence and the pegs serve to hold the workpiece stationary while the table is rotated on the pin to cut an arc about the desired radius.
U.S. Pat. No. 403,618 issued on May 21, 1889 to Abram B. Springstead discloses a work feeder for band saws wherein a segmental frame pivots freely in the horizontal frame about an eye lug set in an adjustable bar. In FIG. 6 a device is shown for rounding the edges of boards where a center bar has a base clamp and a pivoted center. There are spurs that press into the workpiece, holding it in place while a board carrying frame is rotated.
U.S. Pat. No. 1,944,524 issued on Jan. 23, 1934 to George L. Parrish discloses a guiding attachment for band saws where a bar is held in a horizontal position by a telescopic extension placed on the ground. There are two sliding gauge supports movable on the bar and two work engaging members having downwardly extending spurs. There are pivot sockets and clamping devices in each of the gauge members that allow the work engaging members to be clamped in the proper relationship and then rotated to cut a circle or an arc related to a predetermined radius.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.